Apparatus for operating scotch hearths



Deae i, 1935. H. R. MacMl'CHAEL 2,023,484

APPARATUS FOR OPERATING SCOTCH HEARTHS Original Filed April 25, 1928 3 Sheets-Sheet l 2 awuahto'c Dec, 10, 1935.

H. R. M cMlCHAEL APPARATUS FOR OPERATING soo'rcn HEARTHS Original Filed April 25, 1928 3 (lbtomwug Sheets-Sheet 2 awuewtoz 1 M mm WM.M

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APPARATUS FOR OPERATING SCOTCH HEARTHS Original Filed April 25, 1928 '3 Sheets-Sheets m J A .w 9 m 21$: m m. m k- .g k w Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE APPARATUS FOR OPERATING SCOTCH HEARTHS Application April 25, 1928, Serial No. 272,602

6 Claims.

The invention relates in general to the art of metallurgy and more particularly to mechanical operating apparatus for a Scotch hearth.

According to one form of the invention a Scotch hearth is provided with a carriage which may be arranged to move continuously therealong and have mounted thereon various operating mechanisms, such as a poker and shovel for treating the charge.

The poker may be adapted to enter the charge, poke it and level it down, causing parts of the charge to be thrown on the apron of the hearth, in a manner similar to the present manual operation. If desired, a compensating movement 'may be provided. so that the poker is substantially stationary with respect to the movement of the carriage while in the hearth.

The shovel may be arranged to operate upon the charge after the poker and may be arranged to travel over the charge, scraping the apron and flipping part of the charge up against the back of the hearth, forming a bank having the proper slope and condition for best smelting.

Suitable control devices may be provided for causing the carriage to stop at end of its travel and return to its starting position and also for initiating the shovel and poker at proper times. A mechanical shovel which may be employed is disclosed in co -pending application Serial No. 196,304, filed June 3, 1927, and the mechanical poker mechanism which may be employed is disclosed in application Serial No. 200,523, filed June 22, 1927.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is an elevation of the carriage, looking toward the back of the hearth;

Fig. 2 is the detail of the compensating mechanism of the poker;

Fig. 3 is a plan section taken on the line 3-3 of Fig. 1;

Fig. 4 is an elevation section taken on the line 4-4 of Fig. 1, illustrating the operation of the poker; and

Fig. 5 is a section on the line 5-5 of Fig. 1, illustrating the operation of the shovel.

Like reference characters denote like parts in the several figures of the drawings.

In the following description and in the claims 5 parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

In the drawings accompanying and forming part of this specification, a practical commercial embodiment of the invention is shown, but as such illustration is primarily for purposes of disclosure, it will be understood that the structure may be modified in various respects without departure from the broad. spirit and scope of the invention as hereinafter defined and claimed.

Referring now to the drawings, and more particularly to Figs. 4 and 5, so much of a Scotch hearth as is necessary to an understanding of 0 this invention will be described. The Scotch hearth may comprise the usual basin or trough I, the trough being comparatively narrow and. relatively long, as is well understood. At the front edge of the trough, an apron 2 is provided extending the length of the trough, the apron sloping forward and slightly downwardly. At the back side of the trough and extending the length thereof is a back made up of a block 3 having a suitable water space 4 therein for cooling, under- 39 neath which are suitable tuyeres 5 for supplying draft to the furnace, as is well understood in the art. Hoods denoted generally by i2 are provided, their lower ends being disposed close to the hearth efiioiently to catch the fume and gases. This construction is well known and no further description is deemed necessary.

Disposed in front of the hearth overhead is a pair of rails H on which the carriage runs. The carriage comprises a suitable framework in which is journaled a pair of axles 6 and l which have mounted thereon wheels 8 running on rails l l. The carriage carries the mechanical poker 9 and the mechanical shovel In, which will be described in detail hereinafter.

Driving means for the carriage is shown best in Figs. 1 and 4. One axle 6 journaled to rotate in the carriage frame has fixed thereon the wheels 8 and also a spur gear IS. A suitable small electric motor I! may be provided having operative connection with the spur gear through a suitable worm and worm Wheel reduction unit located within the housing l8, this reduction unit driving a small pinion l9 which meshes the spur gear I6. The motor I! may be of the type which mechanism, the main shaft 2| is capable of running forward at a certain speed and running backwards at a diiferent speed.

A suitable reversing switch (not shown) may be provided on the carriage so that, when the carriage reaches the end of its operating trip, the switch will be operated to reverse the motor and drive it backwards at an increased speed to its starting point where the switch will be again operated to reverse the motor and cause it to drive the carriage on its operating trip at a reduced speed.

For driving the poker and shovel mechanisms a separate electric motor 20 is provided mounted on a suitable supporting part of the frame. The main drive shaft 2| is provided suitably journaled in the frame, the drive shaft having a large gear 22 mounted its length. An intermediate shaft 23 is mounted in suitable bearings between the motor 20 and the main shaft 2|, this intermediate shaft having a large gear 24 meshing with the small gear 25 on the motor shaft, and also having a small gear 26 driving the large gear 22 on the main shaft, to give the necessary and desired speed reduction to the main shaft.

The main shaft may have loosely mounted thereon a composite gear 21 made up of a spur gear 28 and bevel gear 29 fixedly secured to each other. The spur gear 28 drives a larger gear 39 located on the rabble shaft 3|. A suitable clutch mechanism 32 controlled by linkage 81 may be provided for selectively connecting and disconnecting the composite gear 2'! to the main shaft 2|.

Mounted in a pair of suitable bearings 33, (Fig. 3) supported by the frame is a crank-shaft 34 having a pair of crank arms 35 and a crank pin 36 therebetween, and an overhung bevel gear 31 meshing with the bevel gear 29 on the main shaft.

Located below the main shaft is the rabble shaft 3|, the rabble shaft being supported in suitable bearings on the framework. In overhung relation on the end of the rabble shaft is a crank 38 for driving the poker device. Also mounted on the rabble shaft 3| is the large gear 30 having feather keyway engagement with the rabble shaft, as shown best in Fig. 2, the gear being fixed longitudinally between suitable bearings 39. Also mounted on the rabble shaft is a pair of spaced collars 40 between which is mounted a sleeve 4| having trunnions 42 projecting therefrom.

Between the crank-shaft 34 and the rabble shaft 3| is a fulcrum bracket having a pivot pin 43 on which is pivoted a lever 44, the lower end of the lever being slotted to engage the trunnions 42, the upper end of the lever being provided with a slot 45 in which the crank pin 36 works.

Supported by the carriage frame and near the front edge of the trough I (Fig. 4) is a support or fulcrum point 46 for the poker 9, this support allowing the poker a motion bodily back and forth in the direction of carriage travel. The poker 9 is provided with a projecting crank pin 50 which is journaled in the crank 38, the crank being provided with a suitable counterweight to counter-balance the weight of the poker.

Referring now more particularly to Figs. 1, 3 and 5 for a description of the shovel operating has loosely mounted thereon a spur gear 55. A suitable clutch device 56, operated by collar 88 which is controlled by a linkage (not shown) similar to linkage 81, is provided for connecting and disconnecting said gear and the main shaft. Below the main shaft the shovel shaft 51 is suitably journaled in the framework of the carriage and has mounted thereon a gear 58 meshing gear 55 and a cam wheel 59. The cam wheel has secured thereto a crank pin 15 having a grooved roller 76 journaled on the end thereof. 5

The framework of the carriage is provided with a pair of lugs or cars to which the impeller arm 60 is pivotally connected by pivot GI and a second pair of spaced ears to which a composite lever 62 (Fig. 1) is pivoted by pivot 63. The frame- 16 Work has a bracket member 54 having aligned openings in which is slidably mounted a follower rod 65 having at its lower end a forked follower member 66. The prongs of the fork have journaled therebetween a roller 61, this roller engag- 15 ing the cam surface on the cam wheel 59.

The follower rod 65 is provided with a suitable abutment 68 between which and the plate 69 is disposed a coil spring 10, this coil spring acting to continuously urge the follower rod against the 20 cam surface. The plate 69 is secured in fixed relations to the bracket member by a pair of rods H disposed on either side of the follower rod.

As shown, te impeller arm $9 is curved at its upper end and generally straight for the rest 25 of its length and has secured to one side thereof a pair of spaced lugs l2. A pair of spaced ways or guides 73 is secured to the lugs, these ways or gnide's being curved, as shown in Fig. 5, to aid in giving the desired peculiar motion to the 30 shovel blade i l. The grooved roller 76 on the end of the crank pin is disposed between these ways.

Pivoted at the lower end of the impeller arm is a shovel arm Ti, this arm comprising a body 35 member having an opening in its middle portion, forming branches (Fig. 3) between which the lower end of the impeller arm is disposed. A suitable pivot bolt ?3 threads the branches and the impeller arm. The front end of the body is 40 suitably forked, and between the prongs of the fork the lower end of the elevating link 19 is suitably pivoted by a pivot bolt 88. The rear end of the shovel arm is provided with the blade '54 of the shovel which extends longitudinally of 45 the furnace a substantial extent and has a slightly back-curved lower end 8 l, as shown in Fig. 5.

The upper end of the elevating link 79 has a suitable loose universal connection with the composite lever 82 to allow the swinging movement 50 of the elevating link back and forth and the upand-down movement imparted thereto by the composite lever. The follower rod 65 has a pivot 33 which works in a slot in the composite lever 52 so that the reciprocating movement of the follower may be imparted to the composite lever.

In operation the carriage will move on its op erating trip from left to right, looking at Fig. 1, and suitable control devices (not shown) will operate the clutch "2 to set the poker in operation 60 as soon as it is opposite the end of the hearth. When the carriage has advanced a little further so that the shovel is opposite the end of the hearth, the control devices will operate clutch 56 to set the shovel in operation. The carriage will 65 travel on its operating trip with both shovel and poker operating until the end of the hearth is reached when suitable control devices (not shown) will cause the carriage to return to the other end of the hearth, both shovel and poker remaining stationary and out of the fire on the return trip, as above described. It will be understood that the clutches 32 and 56 and the devices for controlling the carriage may also be operated by a man walking with the carriage.

The end of the poker will describe a movement somewhat as illustrated by the dotted line 86 in Fig. 4 while it is in the hearth. The charge will be broken up and leveled down and parts of the charge thrown on the apron, as is described in the above co-pending applications. The top of the charge, when thus leveled down, under some conditions is illustrated by line 83 in Fig. 5.

The mechanism will cause the shovel to execute a movement illustrated by the dotted line and arrows indicated by 86 in Fig. 5. This shovel will scrape the apron as shown and push the charge back up, forming the bank which, under some conditions may be illustrated by the line 85 in Fig. 5. The shovel will travel slowly at the front of the hearth but will receive a sudden flip about halfway across the basin which flips the material up against the back of the hearth and causes it to roll forward by gravity, providing a selective action, as explained in the above co-pending applications.

The performance of these functions by the machine described above not only saves the labor of the men formerly required to do this work manually but the work is done much better and more uniformly than could be done manually.

Both shovel and poker are mounted on the carriage at substantially the same level which is just above the apron of the hearth and operate substantially at that level. This allows the hood to be brought close down to the hearth trough, thus minimizing the amount of fume and gas escaping into the room. The shovel and poker are mounted side by side, but far enough apart to prevent the longitudinal compensating movement of the poker from interfering with the operation of the shovel.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In combination with a Scotch hearth, having a long trough and apron, a support, means for relatively moving said hearth and support continuously for operation of the hearth, a rabbler on said support, means for causing said rabbler to enter the hearth and to have substantially no movement in the direction of said relative movement while in said hearth with respect thereto, a shovel on said carriage, and means for imparting a flip to said shovel as it passes over the surface of the material in the hearth, said rabbler operating on said hearth ahead of said shovel, said rabbler leveling the charge and throwing part said charge against the back of the hearth.

2. In combination with a hearth, a support, means for relatively moving said hearth and support continuously for operation of the hearth, a rabbler on said support, means for causing said rabbler to enter the hearth and to have substan- 5 tially no movement thereto while in said hearth in the direction of said relative movement, a shovel on said carriage, and means for imparting a flip to said shovel as it passes over the surface of the material in the hearth.

3. In combination with a Scotch hearth, a support means for relatively moving said hearth and support continuously during operation on the material in the hearth, a poker on said carriage and means for operating said poker, a shovel on said carriage and means for operating the shovel, said shovel having the same relative movement as said carriage, said poker having a compensating movement while in the hearth to compensate said relative movement, said shovel pushing part of said charge against the back of the hearth and causing it to roll down.

4. In combination with a hearth, a support, means for relatively moving said hearth and support continuously during operation on the material in the hearth, a poker on said carriage and means for operating said poker, a shovel on said carriage and means for operating the shovel, said shovel having the same relative movement as said carriage, said poker having a compensating movement while in the hearth to compensate said relative movement.

5. In the art of metallurgy, a Scotch hearth comprising a long trough and a hood fitting close thereover, a poker rod disposed generally horizontally and just above said trough, a shovel rod having a shovel thereon, said shovel rod being also disposed substantially horizontally and close above the trough, a carriage adapted to move along said hearth, means for mounting said shovel rod and poker rod on said carriage and for imparting both lengthwise and up-and-down movements to the ends thereof, said poker rod and shovel rod extending out between said hood and trough, said poker rod and shovel being spaced along said hearth, and means for imparting a motion to said poker rod while it is in the hearth to compensate for the motion of said carriage.

6. In the art of metallurgy, a hearth comprising a long trough and a hood fitting close thereover, a poker rod disposed generally horizontally and just above said trough, a shovel rod having a shovel thereon, said shovel rod being also disposed substantially horizontally and close above the trough, a carriage adapted to move along said hearth, means for mounting said shovel rod and poker rod on said carriage and for imparting both lengthwise and up-and-down movements thereto, said poker rod and shovel rod extending out between said hood and trough.

HUGH R. MACMICHAEL. 

